1. Field of the Invention
The present invention generally relates to authentication methods and units and electronic apparatuses having authentication units, and more particularly to an authentication method and an authentication unit which authenticate users using a non-contact (or contactless or wireless) type medium, such as an IC card and a radio frequency identification (RFID) tag or chip, and to an electronic apparatus, such as an information processing apparatus and an image forming apparatus, having such an authentication unit.
2. Description of the Related Art
Various authentication methods are employed to authenticate (or identify) the user of an apparatus such as an information processing apparatus and an image forming apparatus. The information processing apparatus may be a personal computer or the like. The image forming apparatus may be a printing apparatus, a copying apparatus, a facsimile apparatus, a composite apparatus (or multifunction peripheral) or the like.
For example, a magnetic card may be used for the user authentication by registering the user's ID in the magnetic card. When user authentication is made by contacting and reading the user's ID from the magnetic card in the image forming apparatus.
In addition, a non-contact type IC card may be used for the user authentication. In this case, the user authentication is made when the non-contact type IC card carried by the user is near the image forming apparatus. The user authentication result is maintained and not cancelled as long as the user carrying the non-contact type IC card is near the image forming apparatus to perform a copying operation or the like.
In the case where the non-contact type IC card is used for the user authentication, the user authentication is made when the non-contact type IC card carried by the user is near or passes near the image forming apparatus even if this user does not intend to operate the image forming apparatus. This problem is solved by a method proposed in a Japanese Laid-Open Patent Application No. 2005-32161, for example.
However, in the case of the image forming apparatus that makes the user authentication when the non-contact type IC card is near the image forming apparatus, the IC card must be set near a receiver part of the image forming apparatus while the log-in is made and the user of the non-contact type IC is operating the image forming apparatus, so that the user authentication result is maintained and not cancelled. Hence, the user may forget to remove the non-contact type IC card from the set position near the receiver part of the image forming apparatus after operating the image forming apparatus.
On the other hand, in the case of the image forming apparatus that makes the user authentication when the non-contact type IC card is relatively close to the image forming apparatus (that is, farther away from the “near” position referred above), the IC card does not need to be set near the receiver part of the image forming apparatus while the log-in is made and the user of the non-contact type IC is operating the image forming apparatus, in order to maintain and not cancel the user authentication result. But in this case, the user authentication is made when the user carrying the non-contact type IC is relatively close to the image forming apparatus, even if the user is just passing by and has no intention of operating the image forming apparatus.
Therefore, if the non-contact type IC card must be near the image forming apparatus in order to make the user authentication, the user authentication result will be cancelled when the non-contact type IC card is no longer near the image forming apparatus. On the other hand, if the non-contact type IC card does not need to be near the image forming apparatus and only needs to be relatively close to the image forming apparatus in order to make the user authentication, an unnecessary user authentication is made even when the user carrying the non-contact type IC card moves relatively close to the image forming apparatus without intending to operate the image forming apparatus. In other words, when using the non-contact type IC card for the user authentication in the image forming apparatus, it is difficult to simultaneously prevent the unnecessary (or unwanted) cancellation of the user authentication result and the unnecessary (or unwanted) user authentication.